Shaped body comprising a shaped body shell and a shaped body content, especially capsules with one-piece capsule shell, and method for producing shaped bodies and protective coats

ABSTRACT

This invention concerns a molded part containing a molded part shell and a molded part content, where the molded body shell contains at least one film-forming polymer, that has been selected from a group consisting of polyvinyl alcohols and polyvinyl alcohol derivatives. Preferably the polyvinyl alcohol derivative is a polyvinyl acetal described in EP 771 329. The molded part according to the invention can be used as a primary and/or secondary packing agent. The molded part shell features cumulative positive features such as increases maximum elongation values, odor and taste neutrality, good thermoplastic processing capabilities and excellent biological degradation. The processing of the composition is advantageous to capsules with single-piece shells containing a detergent composition as the molded part content.

[0001] This invention concerns a molded part containing a shell for themolded part and a molded part content, especially capsules withsingle-piece capsule shell, as well as processes for the manufacture ofmolded parts and protective layers according to the generic terms ofindependent patent claims.

[0002] Over the past few years, increased efforts have been made tomanufacture packaging materials from at least partially regenerating andbiologically degradable material. A large number of publications havereferred to starch, starch derivatives, starch mixtures as film-formingbasic materials for the manufacture of packaging, molded parts andfilms, such as EP 118 240, EP 304 401, EP 327 505, EP 397 819, WO90/14938 and EP 479 964.

[0003] In the sense of “one-time packaging”, capsules with appropriatecontent have been increasingly offered for technical purposes, e.g.capsules with bath additives, detergents, dyes for marking objects,aroma additives or cosmetics, etc.

[0004] The capsule shell encloses and “packages” the content in thecorrect amount measured for the application purpose with the correctcomposition. This eliminates the need for the end user to measure outthe quantity of contents required, which is a time-consuming anderror-prone process. The capsule shell must be able to be stored andtransported. After the release of the content, the capsule shellmaterial must not cause any negative side effects. It is very importantthat it can be removed during and after its application withoutreleasing residual substances. These requirements are not fulfilled bythe material currently used for capsule shells, i.e. gelatine. Capsuleshells made of gelatine do not release their content at temperaturesbelow 40° C. due to their inadequate solubility at these temperatures.Even at higher temperatures, the gel often does not dissolve completely.For example, gelatine capsules filled with detergent concentrate canleave non-dissolved gelatine remains on fibers during laundering at 60°C. This residue causes unacceptable damage during ironing. In addition,gelatine capsules filled with bath additives are not accepted by usersif non-dissolved gelatine remains in their bath water. Finally,applications are completely unacceptable in cases where non-dissolvedgelatine clogs filters or pipes, thus putting the due and proper use ofplants and machinery at risk.

[0005] The object of this invention is to eliminate the disadvantages ofthe prior art.

[0006] Especially it is the object of the present invention to providematerials that are appropriate for the manufacture of water-solublemolded parts and films for primary and secondary packaging material.

[0007] It is a further object of this invention to provide materialsthat are appropriate for the manufacturing of molded part shells,especially capsule shells, which are biologically degradable, whosewater solubility can be modified for different temperatures, and whichin particular can be dissolved in cold water.

[0008] These objects are fulfilled through the characteristics of theindependent claims.

[0009] They are especially solved by a molded part comprising a moldedpart shell and a molded part content, whereby the molded part shellcontains at least one film-forming polymer being selected from a groupconsisting of polyvinyl alcohol and derivates of polyvinyl alcohol.

[0010] Within the context of this invention, the term polyvinyl alcoholshould be understood to cover those polyvinyl alcohols which, inaddition to the hydroxyl groups resulting from the polyvinyl alcoholstructure, also contain other functional groups (such as acetyl) up to amaximum of 0.5 mole percent. If the percentage content of functionalgroups which are not hydroxyl groups of the polyvinyl alcohol structureexceeds 0.5 mole percent, then the polymers are called derivates ofpolyvinyl alcohol within the context of this invention. The termderivates of polyvinyl alcohol therefore also includes partiallysaponified polyvinyl alcohols with a residual content of acetyl groupshigher than 0.5 mole percent. The term should, however, only describesuch polymers where the percentage content of polyvinyl alcohol isgreater than, or equal to, 50 percent of the weight in relation to thetotal weight of the polymers.

[0011] In a preferred embodiment, the molded part shells containderivates of polyvinyl alcohol the derivates having a residual contentof acetyl groups of between 13 to 0.5 mole percent, preferably between12 and 1 mole percent.

[0012] Furthermore, derivates of polyvinyl alcohol which contain atleast one acetal group have continued to prove to be especiallysuitable. The acetal groups may be the only functional groups in apolymer in addition to the hydroxyl groups of the polyvinyl alcoholstructure (in the case of the acetalization of polyvinyl alcoholaccording to the definition). They can also occur in combination withother functional groups (such as acetyl groups). This may be the case,for example, where acetalization reactions are performed on the abovedescribed partially saponified polyvinyl alcohols.

[0013] In an alternative embodiment, the object is solved by a moldedpart, comprising a molded part shell and a molded part content, wherebythe molded part shell contains at least one film-forming polymer, whichcontains at least one acetal group per molecule. The polyvinyl alcoholsand derivatives of polyvinyl alcohols as mentioned before could be usedas polymers. As film-forming polymers, polyalcohols could be used,especially polyalcohols selected from the group of polyglycerols,polypropylene glycols and higher derivatives. They should also formacetals with carbonyls or presumptive carbonyls. The acetal group isintroduced into the polyalcohols by means of an acetylation reaction ofat least one polyalcohol with at least one natural agent and/or onederivative of natural agent, the natural agent and/or derivate of thenatural agent comprising at least one carbonyl group or presumptivecarbonyl group. The same natural agents and/or derivatives of naturalagent can be used for the reaction with the polyalcohols as theyare/have been discussed for polyvinyl alcohols and derivatives ofpolyvinyl alcohol. In particular, these are natural agents selected fromthe group consisting of monosaccharides, disaccharides, native andde-polymerized polysaccharides.

[0014] In an especially advantageous embodiment, the molded part shellcontains the polyvinyl alcohol derivatives described in EP 771 329. Thesubject and the disclosure content of EP 771 329 taken as a whole are,therefore, part of this invention. The polyvinyl acetals disclosed in EP771 329 can be manufactured through the acetalization of derivates ofpolyvinyl alcohol(according to the nomenclature of the presentapplication) comprising at least one natural agent, said natural agentand/or natural agent derivates containing at least one carbonyl group orpresumptive carbonyl group and/or natural agent derivatives. Thepolyvinyl alcohol derivatives used for the synthesis of the polyvinylacetals have saponification degrees between 80 and 99.5 mole percent,with the preferred degrees lying between 90 and 99 mole percent. Theacetalization reaction preferably takes place under an acid catalysis.The term presumptive carbonyl group as used in EP 771 329 covers suchnatural agents which form functional groups under acetalizationconditions, and preferably under acid catalyzed acetalizationconditions, which show typical reactions for aldehyde and ketone groups.A typical reaction, for example, is the oxime produced withhydroxylamines. Natural agents and natural agents derivatives containingcarbonyl groups are these natural agents which contain reactive aldehydeor ketone groups. Substances could be included as natural agentderivatives which originate from natural agents as a result ofphysical-mechanical degradation or an enzymatic and/or chemicaldegradation, such as acid or basic catalysed hydrolysis and/or enzymaticand/or oxidative degradation, and which at the same time maintainrespectively form the above mentioned characteristics of carbonyl groupsor presumptive carbonyl groups.

[0015] Regarding the biological degradation capability of the moldedpart shells, EP 771 329 polyvinyl acetals are particularly advantageouswhere the natural agent comprising carbonyl group or the presumptivecarbonyl group is selected from the group consisting of monosaccharides,disaccharides, native and de-polymerized polysaccharides. In the case ofpolysaccharides or, in the case of degraded (de-polymerized)polysaccharides, the oligosaccharides, for example, the reaction takesplace with already present terminal or forming terminal hemiacetalgroups of polymers or oligomers. De-polymerized starch, especiallypotato starch and rice starch, have proven to be especially advantageousas de-polymerized polysaccharide. The water-soluble fractions of theacetalization reaction in particular are used.

[0016] The medium polymerization degrees of the polyvinyl alcoholderivative prior to acetalization are advantageous in the range from 200to 2,700, but preferably in the range from 300 to 1,500, and morepreferably in the range of 400 from 1,000.

[0017] The water solubility of the molded part shell can be varied ormodified by varying the degree of acetalization and polymerization, thatis by varying the chain length. The water solubility of the molded partaccording to invention can be regulated by modifying the medium degreeof polymerization of the polyvinyl acetals. Here refer to theexplanations in EP 771 329.

[0018] The molded part shell can also contain one or more substancesknown for their softening features: water, glycerin, propylene glycol,urea, dimethyl sulfoxide, dimethylformamide,

[0019] N-methyl-2-pyrrolidone, polyoxyketone, hexahydric alcoholsorbitol, sorbitan (cyclical linear ether of hexahydric alcohol),oligomeric hydrated starch degradation products (polysorbitol),polyethylene glycol, fatty acid ester of polyethylene glycol, fatty acidester of glycerin, polyglycerin fatty acid ester, ethoxylated sorbitanfatty acid ester, as well as low molecular polyvinyl alcohols andderivatives. By adding one or more of these compounds, the manufacturedmolded part shells or films can be modified to meet specific requirementprofiles, such as processing at a certain temperature, break resistance,Young's Elasticity Module.

[0020] The softeners are contained in amounts between 0.1 weight percentand 70 weight percent in relation to the total weight of the molded partshell.

[0021] Surprisingly, it has been shown that polyvinyl acetals which havebeen acetalized with starch from EP 771 329 contain a high elasticityeven with just a small percentage of softeners. Water also works as asoftener. A high percentage of water must usually be extracted in aseparate processing step after the molding of the molding body toguarantee the stability of the molded part. These polyvinyl acetalsallow the presence of a small percentage content of water obviating theneed for the additional drying step. A combination of these threecomponents of water, glycerin and hexahydric alcohol has proven to beadvantageous. The addition of glycerol monostearate has another positiveeffect.

[0022] In a preferred embodiment, the molded part shell of the moldedpart contains at least one other polyglycerin with a degree ofpolymerization of greater than, or equal to, four.

[0023] It has been shown that the polyglycerin used as a softener inconjunction with polyvinyl alcohols and derivatives, especially in filmsor in molded parts from EP 771 329, provides surprisingly high maximumelongation values. The absolute value of the elongation which inaddition to the combination of materials is also dependent on therelative amounts of components, is less surprising than the relativeincrease in the maximal elongation in relation to compositionscontaining low molecular homologs of the polyglycerin with the samepercentage weights (i.e. monoglycerin, diglycerin and triglycerin). Whenusing polyglycerin, for example, an increase of the maximal elongationof more than 60 percent can be achieved in comparison to the same weightof glycerin (according to DIN 51562-1-4). Without adhering to thisexplanation, it could be originally based on a very advantageous ratioof the number of hydroxyl groups to the average chain length or theaverage mole weight (weight average). The higher number of hydroxylgroups in comparison to the monomer glycerin is responsible for theincreased formation of hydrogen bridges from the softener to thematrix-forming polymer (smaller migration tendency). Simultaneously, thepolyglycerin can incorporate itself as a softener in between the matrixforming polymer chains and can guarantee their mutual mobility. The termsoftener is defined according to DIN 55945 and the Römpp ChemieLexikon,editors J. Falbe, D. Regitz, Georg Thieme, Verlag Stuttgart, 9^(th)edition, pp. 5017-5020. The softening effect can be measured by meltingpoint and the glass temperature depression (DSC).

[0024] Polyglycerins are used preferably in purities greater than, orequal to, 70 weight percent, or preferably with a purity of 75 weightpercent. This means that the name-giving polyglycerin (e.g.tetraglycerin, hexaglycerin or decaglycerin) is present in weight partsgreater than, or equal to, 70 weight percent of the total weight of thepolyglycerin. The remaining maximum 30 weight percent is distributedamong the lower molecular or higher molecular homologs. The utilizedpolyglycerins are therefore substances with clearly definedchemical-physical characteristics. This guarantees reproducibility withregard to the specific parameter of the composition. Polyglycerins arephysiologically inert, odor and taste neutral, water-soluble, and haveexcellent softening characteristics for the above described polymerswithout migrating from the molded part shell.

[0025] In an advantageous embodiment, the degree of polymerization ofthe polyglycerin comprised in the composition according to the inventionlies within 5 and 20, and preferably between 6 and 12.

[0026] Even more preferable is a polyglycerin with a degree ofpolymerization of 10, the decaglycerin.

[0027] The amount of polyglycerin present in the molded part shellranges from 0.1 weight percent to 70 weight percent in relation to thetotal weight of the molded part shell. The preferred weights lie between10 weight percent and 40 weight percent. Polyglycerin of only one degreeof polymerization can be utilized as well as mixtures of polyglycerinswith varying degrees of polymerization. The structure of thepolyglycerin(s) can be linear, branched or cyclical.

[0028] The term molded part, used to differentiate from protectivelayers which can also be manufactured with the same composition as themolded part, consists of an integral body of any form and thicknesswhich can be manufactured without a formally attached and supportingmaterial, and which can be utilized self-supported.

[0029] In the molded part shell of the molded part according to theinvention, several relevant and necessary advantages for packingmaterials are combined. The molded part form shell or the material ofthe molded part shell can be modified in such a way that they are watersoluble or water dispersible in water temperatures below 40° C., andpreferably below 35° C. It is almost 100% biologically degradable, odorand taste neutral, and can be adjusted to high elongation values at theprocessing temperature. These features make them extremely suitable foruse as primary or secondary packaging materials. A packaging agent is amolded shell which is normally separate from the packed content, such asbottles, foil, bags, etc. prior to its application or use. Primarypacking agents come directly into contact with the package contents,whereas secondary packing agents only come into contact with the primarypackaging material. In a preferred embodiment, the primary packingagents are actually part of the product. The shell and contents are partof the application. No opening of the actual content is necessary.Examples from the food industry are soup powder, which is filled into ahose bag and then immersed in water. Examples from the technical fieldare fertilizers or pesticides which are provided with the shell. Theuser's safety is significantly increased. A preferred embodiment of sucha primary packaging agent is the molded part shell in the design of acapsule comprising capsule content and capsule shell.

[0030] In another embodiment, the molded part content of a first moldedpart according to the invention is a second molded part according to theinvention. Preferably the second molded part is a capsule. The shell ofthe first molded body therefore serves the function of a secondarypacking agent for the second molded part, whose shell serves thefunction of a primary packing agent. The material of the secondary andprimary packing agent is selected from a group of same materials. Thesematerials are compositions as already described and are preferablypolyvinyl acetals described in EP 771 329 in addition to theadvantageous additives already described. In a preferred embodiment, thepacked, molded part, that is the first molded part enclosed in asecondary packing agent, is a capsule with a single-piece capsule shelland a liquid detergent composition as capsule content. The first moldedpart can be applied together with a secondary packing agent. In additionto the aspect of childproof packaging of the first molded part, thetime-consuming opening of the molded part is obviated. Additionalsubstances being not suitable for encapsulation can be incorporated inthe secondary packaging agent. As the secondary packaging agent isalmost 100% biologically degradable, there are no costs involved in thedisposal of the secondary packaging agent.

[0031] The molded parts can be produced in all conceivable forms basedon the high elongation values of the material that forms the molded partshell, especially when formed as a film. The thermoplasticity allows theproduction of packing forms by other production technologies (such aspouring, dipping, injection molding, co-injection molding, extrusion toflat film, bale film etc.).

[0032] As has been mentioned already, a preferred embodiment of themolded part according to the invention is a capsule with a single-pieceor two-part capsule shell. The capsule shell can be manufactured usingthe one or two-part rotary-die-process.

[0033] The encapsulation of liquid and pasty content materialspresupposes a single-piece capsule shell. Automated continuousmanufacturing processes are prevalently used for liquid, and in abroader sense pumpable, capsule contents. The manufacture of capsuleshells and their filling takes place in one single step. In thiscontinuous “one-step process”, molded parts are produced, with thecapsule shell being closed during and after filling by welding the outeredges of the molded parts. The production of molded parts takes placeusing molds which come together or move apart, such as in the Norton,Banner and Schering processes, or with rotating roller presses, such asin the rotary die process and in the Accogel process (“The Capsule”,edited by Fahrig/Hofer, Stuttgart, 1983). Filling takes place with thehelp of dosage pumps that fill a defined amount of the content materialduring the die-cutting and molding of the molded parts. The welding,that is the formation of the seams, generally takes place by means ofpressure and heat. The production costs are significantly lower thanwhen using die casts for two-part cachet shells.

[0034] The manufacturing process for single-piece capsules, especiallythe rotary die process, places several demands on the capsule shellmaterial. One of the main requirements is the capability of the capsuleshell material to form highly elastic “endless” tapes of adequatestrength. Therefore, the Young Elasticity Module E of the film must notlie above higher than 2 Mpa, and preferably not below 1 Mpa, at themoment of the remolding and filling during the rotary die process. Inother words, the film must not offer any resistance to the fillingpressure of the filling material, which effectively causes the formationof the capsule shell during the rotary die process, caused through theweight pressure of the filling nozzle, such that the filling materialruns between the filling nozzle and the film. Additionally, the hardnessam of the capsule shell material must have under the standard conditions(of 25° C. and 60% relative humidity) a value of at least 2 MPa toguarantee sufficient stability of the capsule shell at room temperature(based on storage, transport safety and usage requirements).Furthermore, the capsule shell material should be able to be welded toensure sufficient stability of the seams. The material of the moldedpart shell for the molded part according to the invention fulfills theserequirements in all aspects. In a preferred embodiment, σ_(m) is greaterthan, or equal to, 3.5 MPa, and is preferably greater than, or equal to,5 MPa. The capsule shell material must also be compatible with a varietyof content materials.

[0035] In addition, part of this invention is a process for theproduction of a molded part, and especially for the production of acapsule with a single-piece capsule shell. The process includes thefollowing steps:

[0036] a) Providing of a composition containing at least onefilm-forming polymer selected from a group of polyvinyl alcohols andpolyvinyl alcohol derivatives. The composition contains at least oneadditive in the range from 0.1 to 70 weight percent in relation to thetotal weight of the composition that has been selected from a groupconsisting of water, glycerin, propylene glycol, urea,N-methyl-2-pyrrolidone, dimethyl sulfoxide, dimethylformamide,polyoxyketone, hexahydric alcohol, sorbitan, oligomeric hydrated starchdegradation products, polyethylene glycol, polyethylene glycol fattyacid ester, glycerin fatty acid ester, polyglycerin fatty acid ester,ethoxylated sorbitan fatty acid ester, as well as polyvinyl alcohols andderivatives thereof and polyglycerin with a degree of polymerizationgreater than, or equal to, four;

[0037] b) Heating of said composition to a flow temperature, preferablyin the range between 40° C. and 130° C.;

[0038] c) Molding, in particular extrusion of the composition at flowtemperature, as a film, the film preferably having thickness of between0.01 and 2.0 mm;

[0039] d) Optionally intermittent storage of the film;

[0040] e) Remolding of the film into a molded body, especially into acapsule with a single-piece capsule shell using an intermittent orcontinuous molding process, in particular using a continuous mold andfill process.

[0041] In a preferred embodiment, the used continuous form and fillingprocess in e) for the production of filled capsules with single-piececapsule shell is the rotary die process.

[0042] The components of the provided composition as described in a) canbe transformed in a preceding step into a preferred homogeneous,storage-stable form, such as granulate. The composition can be processedfurther after storage. Alternatively, the transformation of thecomposition into a homogenous state can take place during the heatingstage in step b).

[0043] In a more preferred embodiment, the film extruded by the extruderis fed directly to the remolding device, that is without intermittentstorage of the film in the sense of an in-line production.

[0044] One-piece capsules produced using the above mentioned process areexceptionally interesting for technical applications as thewater-solubility of the capsule shells can be adjusted in certaintemperature ranges. It is possible, for example, to produce capsuleswhich release their content material at water temperatures of between25° C. and 30° C. This is not possible with the gelatine-based capsulescurrently available. This feature is especially relevant for theencapsulation of highly concentrated detergent and tenside compounds. Itallows the dissolution of the capsule shell, and thus washing, attemperatures below 40° C.

[0045] In a preferred embodiment, the molded body according to theinvention contains a content of a preferably liquid detergentcomposition.

[0046] The detergent composition ideally contains as tensideN-monoisopropanol ammonium, N,N-diisopropanol ammonium andN,N,N-triisopropanol ammonium salts of fatty alcohols (C₁₂-C₁₄)poly-ethylene glycol (2EO) ether sulfates, or mixtures thereof.

[0047] In order to be considered suitable for the encapsulation in watersoluble or water dispersible capsule materials, the tensides mustfulfill specific requirements regarding the mole weight, the moleculeform, the pH value, the water content, viscosity and the chemicalreactivity. These requirements must be fulfilled for reasons ofcompatibility of the capsule material with the capsule shell and withother components in the detergent composition, the storage stability ofthe capsule, the biological degradation, the dissolution and releaseconduct in water, the washing activity, the encapsulation technology,and the user application (light weight, space-saving). The above namedalkanol ammonium salts of fatty alcohol polyethylene glycol ethersulfate fulfill these criteria almost ideally in combination with themolded body shells of the invention. The detergent composition cancontain other common additives, such as enzymes, other tensides,fillers, graying inhibitors, bleaches, etc.

[0048] In addition, the water solubility of the capsule shell can bemodified in such a way that it only dissolves at high temperatures. Thisfeature makes the capsules interesting for the encapsulation of contentmaterial, which can either be pumped or which only exist in liquid stateat higher temperatures and which can therefore be enclosed only athigher temperatures. These content materials can also contain a certainpercentage of water without damaging the capsule shell.

[0049] The same composition mentioned in a) can be processed using diecasting into molded bodies and especially into so-called hard capsules,that is into two-part capsules. This process includes providing andmixing of the components of the composition, or providing the alreadyhomogeneous composition in a first step, its transformation into aflowable state, which normally requires temperatures of between 40° C.and 130° C., a subsequent die casting of the composition heated to aflow temperature in pre-manufactured die cast mold parts, followed byde-molding from the die casting form parts during or after the coolingof the composition.

[0050] The forming of the hard capsules can also take place by dippingthem in a molten mass (solution) diluted by water or alcohol.

[0051] Alternatively, the composition named under a) can be applied to abody of any shape by means of dipping and spraying in order to create aprotective layer. This protective layer could be removed throughdissolution, for example with water, before additional processing orapplication. The composition is dissolved for the dipping or sprayingprocess in a solvent. Preferred solvents are water, low molecularalcohols such as methanol, ethanol, butanol, or mixtures of thesesolvents. Dipping can also take place out of a molten mass. In thiscase, the solvent is omitted.

[0052] In addition, part of the invention is a composition for theproduction of form bodies and protective layers containing at least onepolyglycerin with a degree of polymerization greater than, or equal to,four, and at least one polymer selected from a group consisting ofstarch and starch derivatives.

[0053] In the sense of the invention, starch includes native starch aswell as physically modified starch, but essentially not de-polymerizedstarch, such as swelling starch. The starches are not limited to aselection of certain plants producing them. The selection of thestarches (potato starch, rice starch, corn starch, etc.) depends ontheir usage.

[0054] All starches whose primary polymer structure has been modified(de-polymerized starches, chemical foreign groups carrying modifiedstarched) should be included under the term of starch derivatives withinthe context of this invention. De-polymerized starches are appropriatefor the composition according to the invention.

[0055] Preferred starch derivatives are, however, chemically modifiedstarch derivatives. The percentage starch content should be greaterthan, or equal to, 20 w/w. Preferably, the percentage starch contentshould be greater than, or equal to 30 w/w, and more preferably itshould be 50 w/w in order to be included under the term starchderivative. Starch derivatives that have been modified (acetalized) withpolyvinyl alcohols are suitable for the composition according to theinvention.

[0056] Those starch derivatives which have proven to be especiallyuseful are derivatives with acetalically bonded polyglycerin compounds.During the process, polyglycerin/starch copolymers are formed. Ingeneral, the derivatization reagent occurs, independently of thederivatization process, as a reaction with the amylose as well as withthe amylopectin molecules. The distribution of foreign groups in theamylose molecules and the amylopectin molecules varies, among otherfactors (such as the manufacturing method), according to theaccessibility of the amylose and amylopectin chains in the starch forthe derivatization reagent. These effects are known to experts and willnot be explained further.

[0057] It might be necessary for certain application purposes to eitheruse only the derivatives of the amylose molecules acetalized withpolyglycerin or only the amylopectin acetalized with polyglycerin. Thispresupposes, however, the separation of amylopectin and amylosemolecules, which can take place either prior to or following thederivatization reaction.

[0058] The copolymer polyglycerin/starch assumes the purpose of aninterior softener (definition of internal softener according to Rompp,9. Edition). The production of this starch/polyglycerin copolymer cantake place analogous to the syntheses described in EP 771 329 orPCT/AT96/00093. The production method is, however, not just limited tothis method. The copolymerization of the starch with polyglycerin ispreferably performed with polyglycerins which have a degree ofpolymerization up to, or equal to, 10.

[0059] The composition can also contain, in addition to thestarch/polyglycerin copolymer, non-bonded polyglycerins. These could benon-reacted polyglycerins from the synthesis which have not been removedafter the copolymerization. Alternatively, polyglycerin(s) can be addedon demand to the copolymer.

[0060] The copolymer starch/polyglycerin can be processed into moldedparts of any form based on the internal softening effect even withoutany additional non-bonded polyglycerin. Part of this invention is,therefore, a composition for the production of molded parts andprotective layers containing at least one copolymer of starch andpolyglycerin, whereby at least one type of polyglycerin is boundacetalically to the starch.

[0061] Polyglycerin can also be bound acetalically to cellulosemolecules. In polyglycerin/cellulose copolymers, the internal softeningeffect described for starch/polyglycerin copolymers takes place incompositions used for the production of molded parts. Thecellulose/polyglycerin copolymers can contain non-bonded polyglycerin inone composition, but can be processed into molded parts without thepresence of non-bonded polyglycerin. Part of this invention is further acomposition for the manufacture of molded parts and protective layerswhich contains at least one copolymer of cellulose and polyglycerin,whereby at least one type of polyglycerin is bound acetalically to thecellulose. The chain length of the cellulose molecules has been selectedin such a way that a derivatization is possible.

[0062] In the description of this invention, the technical terms aredefined according to Römpp, Chemielexikon [Chemical Lexicon], Editors J.Falbe, M. Regitz, Georg Thieme Verlag, Stuttgart, 9. Edition unlesstheir meaning is explicitly described.

[0063]FIG. 1 shows a first molded part according to the invention thatis encased by a second molded part according to the invention as afunction of a secondary packaging agent (cross section)

[0064]FIG. 2 shows several first molded parts according to the inventionthat are all encased by a second molded part as a function of asecondary packaging agent.

[0065]FIG. 1 shows a first molded part 1 according to the invention inthe form of a capsule with a single-piece capsule shell 4 and a capsulecontent (not shown), for example a detergent concentrate. The moldedpart 1 is enclosed by a second molded structure 2, the secondary package2, in order to be childproof and to increase storage stability,respectively safety and transport stability. The secondary package 2 canconsist of two pieces 2 a and 2 b, which can be formed through drawingof the foil. The two parts are connected at their contact surface 3 aand 3 b. Depending on their material composition, they are either gluedor welded together. Depending on the material, glue can be applied orthe material develops glue features when moistened. The secondarypackage 2 and the molded part shell 4 of the molded substance 1according to the invention, the primary package, are manufactured fromthe same or from similar materials, and contain a film-forming polymermaterial at least one polyvinyl acetal according to EP 771 329 and atleast one additive mentioned in the introduction part of thedescription. This design has the advantage that the molded part withcontent, plus the secondary package, is supplied for the finalapplication. A time-consuming opening of the secondary package of themolded part and/or opening of the molded part content from the primarypackage is thus obviated.

[0066]FIG. 2 shows several molded parts 1 that are totally enclosed by asecond molded part 2, the secondary package 2. In the shown embodiment,the secondary package has been molded from one piece with breaking ties5 in order to allow the individual molded parts according to theinvention and their secondary packages to be provided for theirapplication purpose.

EXAMPLES Example 1

[0067] Base compound: Polyvinyl acetal (according to EP 771329)granulate type 3-90/9/2T5 (reference Constan- tia/Vienna) Composition:68% base compound  8% water 22% glycerin  1% glycerin monostearate  1%lecithin Strip manufacture: Chill roll extrusion Strip thickness 600 μmCapsule manufacture: Rotary die process Fill material: Paraffin oilCharge: 0.5 g/capsule Form: Oval Drying: Not applicable Test: Capsuleshell completely soluble in water at 19° C.

Example 2

[0068] Base compound: Polyvinyl acetal (according to EP771329) granulatetype 3.5/11/1 (reference Constan- tia/Vienna) Composition: 68% basecompound  8% water 22% glycerin  1% glycerin monostearate  1% lecithinStrip manufacture: Chill roll extrusion Strip thickness 600 μm Capsulemanufacture: Rotary die process Fill material: Paraffin oil Charge: 0.5g/capsule Form: Oval Drying: Not applicable Test: Capsule shellcompletely soluble in water at 19° C.

Example 3

[0069] Base compound: Polyvinyl acetal (according to EP771329) granulatetype 3-40/9 (Reference Constan- tia/Vienna) Composition: 65% basecompound  4% water 10% glycerin 20% sorbitol  1% glycerin monostearateStrip manufacture: Chill roll extrusion Strip thickness 600 μm Capsulemanufacture: Rotary die process Fill material: Paraffin oil Charge: 1g/capsule Form: Round Drying: Not applicable Test: Capsule shellcompletely soluble in water at 19° C.

[0070] In a comparison test, an acetalized polyvinyl alcohol accordingto EP 771 329 (type 3-90/9/2T5/Constantia Vienna) of the composition: 41weight percent starch; 11% glycerin and 8.4% water was mixed once withglycerin (Example 4) and once with the same weight of decaglycerin(Example 5). Example 4 Example 5 63 g Extrudate 63 g Extrudate 14 gGlycerin 14 g Decaglycerin

[0071] Both components were transformed in a Brabend kneader at 130° C.into a homogeneous composition and pressed to a film of 600 μm.alternatively, it can be melted in an extruder (fine combed, twin screwextruder turning in the same direction at 80-130° C.; 50-300 rpm) andthen extruded to film through a wide slot nozzle onto cooled rolls <40°C. The film's elongation was measured according to DIN 51 562-1 −4 at21° C. and 21% relative humidity an average value from four individualmeasurements. Example 1 Example 2 Max. measured elongation [in %]:141.99 214.79 Elongation [MPa]: 4.65 3.27 Young's Elasticity Module(Mpa) 40.34 12.54

1. Molded part containing a molded part shell and a molded part content,characterized in that the molded part shell contains at least onefilm-forming polymer that has been selected from a group consisting ofpolyvinyl alcohols and polyvinyl alcohol derivatives.
 2. Molded partaccording to claim 1, characterized in that the polyvinyl alcoholderivatives has a residual content of acetyl groups between 13 and 0.5mole percent, preferably between 12 and 1 mole percent.
 3. Molded partaccording to claim 1 or 2, characterized in that the polyvinyl alcoholderivatives has at least one acetal group per molecule.
 4. Molded partaccording to claim 3, characterized in that the acetal group isintroduced through an acetalization reaction of at least one polyvinylalcohol derivative with at least one natural agent and/or natural agentderivative, said natural agent and/or natural agent derivativecontaining at least one carbonyl group or presumptive carbonyl group. 5.Molded part according to one of the claims 1 to 4, characterized in thatthe average degree of polymerization of the polyvinyl alcohols and/or ofthe polyvinyl alcohol ranges between 200 and 2700, preferably between300 and 1500, and more preferably between 400 and
 1000. 6. Molded partcomprising a molded part shell and a molded part content, characterizedin that the molded part shell contains at least one film-formingpolymer, said polymer containing at least one acetal group per molecule.7. Molded part according to claim 6, characterized in that the acetalgroup is introduced through an acetalization reaction of at least onepolyalcohol with at least one natural agent and/or natural agentderivatives, said natural agent and/or natural agent derivativecontaining at least one carbonyl group or presumptive carbonyl group. 8.Molded part according to claim 7, characterized in that the polyalcoholhas been selected from the group of polyglycerides, polypropylene glycoland higher derivatives.
 9. Molded part according to claim 4 or 7,characterized in that the natural agent is selected from a groupconsisting of monosaccharides, disaccharides, native and de-polymerizedpolysaccharides.
 10. Molded part according to claim 9, characterized inthat the de-polymerized polysaccharide is de-polymerized starch,preferably potato starch.
 11. Molded part according to one of the claims1 to 10, characterized in that the molded part shell contains at leastone more substance ranging from 0.1 to 70 weight percent in relation tothe total weight of the molded part shell, which is selected from agroup consisting of water, glycerin, propylene glycol, urea, dimethylsulfoxide, dimethylformamide, N-methyl-2-pyrrolidone, polyoxyketone,hexahydric alcohol, sorbitan, oligomeric hydrated starch degradationproducts, polyethylene glycol, polyethylene glycol fatty acid ester,glycerin fatty acid ester, polyglycerin fatty acid ester, ethoxylatedsorbitan fatty acid ester, as well as polyvinyl alcohols and derivativesthereof.
 12. Molded part according to one of the claims 1 to 11,characterized in that the molded part shell contains at least onepolyglycerin with a degree of polymerization of greater than, or equalto, four.
 13. Molded part according to claim 12, characterized in thatthe polyglycerin is decaglycerin.
 14. Molded part according to one ofthe claims 12 or 13, characterized in that the polyglycerin is presentin an amount of between 0.1 weight percent and 70 weight percent,preferably between 10 weight percent and 40 weight percent in relationto the total weight of the molded part shell.
 15. Molded part accordingto one of the claims 1 to 14, characterized in that the content has asolid, paste-like, liquid or gaseous consistency.
 16. Molded partaccording to claim 15, characterized in that the molded part content ispreferably a liquid detergent composition.
 17. Molded part according toclaim 16, characterized in that the detergent composition containstensides which are selected from the group consisting ofN-monoisopropanol ammonium, N,N-Diisopropanol ammonium andN,N,N-Triisopropanol ammonium salts of the fatty alcohol (C₁₂-C₁₄)polyethylene glycol (2EO)ether sulfates.
 18. Molded part according toone of the claims 1 to 17, characterized in that the molded part is acapsule with a one or two-part shell.
 19. Molded part according to claim16, characterized in that the capsule can be manufactured by the rotarydie process.
 20. Production process of a molded part, preferablycapsules with single-piece capsule shells comprising the followingsteps: a) Providing a composition containing at least one polymerselected from a group of polyvinyl alcohols and polyvinyl alcoholderivatives, whereby the composition contains at least one additivebetween 0.1 and 70 weight percent in relation to the total weight of thecomposition that has been selected from a group consisting of water,glycerin, propylene glycol, urea, N-methyl-2-pyrrolidone, dimethylsulfoxide, dimethylformamide, polyoxyketone, hexahydric alcohol,sorbitan, oligomeric hydrated starch degradation products, polyethyleneglycol, polyethylene glycol fatty acid ester, glycerin fatty acid ester,polyglycerin fatty acid ester, ethoxylated sorbitan fatty acid ester, aswell as polyvinyl alcohols and derivatives thereof and polyglycerin witha degree of polymerization greater than, or equal to, four; b) Heatingof this composition to a flow temperature, preferably at between 40° C.and 130° C.; c) Molding, especially extruding of the composition at flowtemperature as film; d) Optionally intermittent storage of the film; e)Remolding of the film into a molded body, preferably into a capsule witha single-piece capsule shell, using an intermittent or continuousmolding process, in particular using a continuous mold and fill process.21. Molded part according to claim 20, characterized in that thecontinuous molding process is the rotary die process.
 22. Process forthe production of a molded part, preferably of a two-part capsule shellwith the following steps: a) Providing a composition containing at leastone polymer selected from a group of polyvinyl alcohols and polyvinylalcohol derivatives, whereby the composition contains at least oneadditive between 0.1 and 70 weight percent in relation to the totalweight of the composition that has been selected from a group consistingof water, glycerin, propylene glycol, urea, N-methyl-2-pyrrolidone,dimethyl sulfoxide, dimethylformamide, polyoxyketones, hexahydricalcohol, sorbitan, oligomeric hydrated starch degradation products,polyethylene glycol, polyethylene glycol fatty acid ester, glycerinfatty acid ester, polyglycerin fatty acid ester, ethoxylated sorbitanfatty acid ester, as well as polyvinyl alcohols and derivatives thereofand polyglycerin with a degree of polymerization greater than, or equalto, four; b) Heating of this composition to a flow temperature,preferably at between 40° C. and 150° C.; c) Die casting of thecomposition brought to flow temperature in a pre-produced die castingmold; d) De-molding of the die-cast molded parts in c) from thedie-casting form during or after cooling.
 23. Process for the productionof a protective layer characterized by the following steps: a) Providinga composition containing at least one polymer selected from a group ofpolyvinyl alcohols and polyvinyl alcohol derivatives, whereby thecomposition contains at least one additive in the range of 0.1 to 70weight percentages regarding the total weight of the composition thathas been selected from a group consisting of water, glycerin, propyleneglycol, urea, N-methyl-2-pyrrolidone, dimethyl sulfoxide,dimethyl-formamide, polyoxyketones, hexahydric alcohol, sorbitan,oligomeryc, hydrated starch degradation products, polyethylene glycol,polyethylene glycol fatty acid ester, glycerin fatty acid ester,polyglycerin fatty acid ester, ethoxylated sorbitan fatty acid ester, aswell as polyvinyl alcohols and derivatives thereof and polyglycerin witha degree of polymerization greater than, or equal to, four; b)Dissolving of the composition in an appropriate solvent or solventmixture; c) Dipping or spraying the solution on a body of any form; d)Drying of the solution by extracting the solvent.
 24. Molded formaccording to one of the claims 1 to 16, where the molded part content isa second molded part according to one of the claims 1-16.